JP4961725B2 - Synchronous motor control device and control method thereof - Google Patents

Description

  The present invention relates to a control apparatus and a control method for a synchronous motor.

  In recent years, electric motors that are widely used in automobiles have strict demands for miniaturization and efficiency for automobile applications. Currently, many automobiles equipped with electric motors for running are hybrid cars that run by combining engine output and motor output, and many have two motors for generator and motor use. As a means for realizing miniaturization and high efficiency of such a hybrid vehicle motor, the present applicant has proposed Japanese Patent No. 3480301 (refer to Patent Document 1).

According to the present invention, it is possible to independently rotate two rotors by supplying a composite current to one stator, and it is possible to generate torque for two motors with one motor physique. In addition, the average value of the current applied to the stator in accordance with both rotors is lower than the average value when the current is simply applied to the two motors, and there is an effect that the loss due to the current is reduced. Further, the present applicant has developed an electric motor that can achieve the above-described effects with a single rotor (details will be described later).
Japanese Patent No. 3480301 (paragraph [0010-0012], FIG. 1)

  However, since the electric motor in the above-described invention supplies current corresponding to the number of pole pairs, there is a problem that iron loss due to higher-order components of the current magnetic flux becomes relatively large and the electric motor efficiency is lowered. . Therefore, the present invention provides a highly efficient driving technique for all the operating points of the motor represented by the rotational speed and the output torque for the above-described electric motor.

In order to solve the above-mentioned problems, a control device for a synchronous motor according to a first invention
One rotor consisting of a group of rotors each having a plurality of rotors each having a different number of pole pairs and coaxially connecting the rotors (so as not to rotate relative to each other) Each rotor that can be driven / rotated is mechanically connected to rotate integrally as one rotor), or multiple magnetic fluxes with different number of pole pairs (such as those generated from a set of multiple magnets) Control of a synchronous motor composed of any one rotor having a superimposed space magnetic flux and a stator capable of generating a plurality of rotating magnetic fields corresponding to the number of pole pairs. A device,
Comparing at least one of the rotational speed and output torque of the synchronous motor with a predetermined value, and corresponding to the result of the comparison , corresponding to the combined power supply mode for generating a rotating magnetic field corresponding to the number of pole pairs and the number of pole pairs A power supply mode switching means (for example, a circuit) for switching between a single power supply mode for generating a rotating magnetic field,
It is characterized by including.

A control device for a synchronous motor according to a second invention is:
The power supply mode switching means is
When the output torque of the synchronous motor is greater than a predetermined value, the combined power supply mode,
When the rotational speed of the synchronous motor is larger than a predetermined value, a single power supply mode corresponding to the number of pole pairs smaller than the number of pole pairs,
In other cases (when the output torque and rotational speed of the synchronous motor are other than the above), the single power supply mode corresponding to a large number of pole pairs among the number of pole pairs,
Select each
It is characterized by that.

A control device for a synchronous motor according to a third invention is
The power supply mode switching means is
When the rotational speed of the synchronous motor is greater than a first predetermined value, the single power supply mode corresponding to a large number of pole pairs among the number of pole pairs,
When the rotational speed of the synchronous motor is greater than a second predetermined value (where the second predetermined value> the first predetermined value), the single power supply mode corresponding to the smaller number of pole pairs out of the number of pole pairs;
In other cases (when the rotational speed of the synchronous motor is other than the above), the combined power supply mode,
Select each
It is characterized by that.

A control device for a synchronous motor according to a fourth invention is:
The power supply mode switching means is
When the rotational speed of the synchronous motor is greater than a predetermined value, the single power supply mode corresponding to the small number of pole pairs among the number of pole pairs,
In other cases (when the rotational speed of the synchronous motor is other than the above), the combined power supply mode,
Select each
It is characterized by that.

A control device for a synchronous motor according to a fifth invention is:
The power supply mode switching means is
When the output torque of the synchronous motor is greater than a first predetermined value, the single power supply mode corresponding to the number of pole pairs that is large among the number of pole pairs,
When the output torque of the synchronous motor is larger than a second predetermined value (where the second predetermined value> the first predetermined value), a composite power supply mode,
In other cases (when the output torque of the synchronous motor is other than the above), the single power feeding mode corresponding to the small number of pole pairs among the number of pole pairs,
Select each
It is characterized by that.

The synchronous motor control apparatus according to the sixth invention is
The power supply mode switching means is
At each operating point of the synchronous motor represented by the rotational speed and the output torque, a power supply mode in which the input / output efficiency of the synchronous motor is higher is selected from the composite power supply mode and the single power supply mode. ,
It is characterized by that.

A control device for a synchronous motor according to a seventh invention is:
The power supply mode switching means is
When the operating point changes from the first operating point to the second operating point at the operating point of the synchronous motor represented by the rotational speed and the output torque, a predetermined time elapses at the second operating point. Until the power supply mode at the first operating point is maintained, and the power supply mode at the second operating point is switched after the predetermined time,
It is characterized by that.

A control device for a synchronous motor according to an eighth invention is
The power supply mode switching means is
When the power supply mode is switched, the distribution ratio of each of the rotating magnetic fields corresponding to the number of pole pairs required in the power supply mode before and after the switching is changed temporally so that the output torque of the synchronous motor is continuous before and after the switching. ,
It is characterized by that.

A control device for a synchronous motor according to a ninth invention
The power supply mode switching means is
In the single power supply mode corresponding to the driving of one pole pair, the other pole is controlled so as to suppress the induced voltage generated in the winding constituting the stator due to the number of the other pole pair that is not fed (driven). Superimposing a field weakening current corresponding to the logarithm on the current in the single power supply mode,
It is characterized by that.

A control apparatus for a synchronous motor according to a tenth invention is
The rotor is
Regarding the number of pole pairs, the phase difference between the respective magnetic poles is configured with a phase difference that minimizes the peak value of the induced voltage waveform generated in the windings constituting the stator.
It is characterized by that.

A control device for a synchronous motor according to an eleventh invention is
The number of pole pairs is two pole pairs of P1 and P2 (where P1 <P2);
The phase difference between these magnetic poles is:
Phase difference [mechanical angle (degree)] = 90 × (1 / P1-1 / P2)
Satisfy,
It is characterized by that.

A synchronous motor control device according to a twelfth aspect of the present invention is
The deviation angle from the angle given by the phase difference formula is within −20% to + 20%.
It is characterized by that.

As described above, the solution of the present invention has been described as an apparatus. However, the present invention can be realized as a method, a program, and a storage medium storing the program, which are substantially equivalent thereto, and the scope of the present invention. It should be understood that these are also included.
For example, when the first invention is realized as a method, the synchronous motor control method according to the thirteenth invention is:
One rotor consisting of a group of rotors each having a plurality of rotors each having a different number of pole pairs and coaxially connecting the rotors (so as not to rotate relative to each other) Either a rotor that can be driven and rotated is mechanically connected to rotate integrally as one rotor), or a single rotor having a spatial magnetic flux in which a plurality of magnetic fluxes having different numbers of pole pairs are superimposed. A control method for a synchronous motor comprising one of the rotors and a stator capable of generating a plurality of rotating magnetic fields corresponding to the number of pole pairs,
Comparing at least one of the rotational speed and output torque of the synchronous motor with a predetermined value, and corresponding to the result of the comparison , corresponding to the combined power supply mode for generating a rotating magnetic field corresponding to the number of pole pairs and the number of pole pairs A power supply mode switching step for switching between a single power supply mode for generating a rotating magnetic field,
It is characterized by including.

A method for controlling a synchronous motor according to a fourteenth aspect of the invention includes
The power supply mode switching step includes
When the output torque of the synchronous motor is greater than a predetermined value, the combined power supply mode,
When the rotational speed of the synchronous motor is larger than a predetermined value, a single power supply mode corresponding to the number of pole pairs smaller than the number of pole pairs,
In other cases (when the output torque and rotational speed of the synchronous motor are other than the above), the single power supply mode corresponding to a large number of pole pairs among the number of pole pairs,
Select each
It is characterized by that.

A control method of a synchronous motor according to the fifteenth aspect of the invention is
The power supply mode switching step includes
When the rotational speed of the synchronous motor is greater than a first predetermined value, the single power supply mode corresponding to a large number of pole pairs among the number of pole pairs,
When the rotational speed of the synchronous motor is greater than a second predetermined value (where the second predetermined value> the first predetermined value), the single power supply mode corresponding to the smaller number of pole pairs out of the number of pole pairs;
In other cases (when the rotational speed of the synchronous motor is other than the above), the combined power supply mode,
Select each
It is characterized by that.

A control method for a synchronous motor according to a sixteenth invention is
The power supply mode switching step includes
When the rotational speed of the synchronous motor is greater than a predetermined value, the single power supply mode corresponding to the small number of pole pairs among the number of pole pairs,
In other cases (when the rotational speed of the synchronous motor is other than the above), the combined power supply mode,
Select each
It is characterized by that.

A control method for a synchronous motor according to a seventeenth invention is
The power supply mode switching step includes
When the output torque of the synchronous motor is greater than a first predetermined value, the single power supply mode corresponding to the number of pole pairs that is large among the number of pole pairs,
When the output torque of the synchronous motor is larger than a second predetermined value (where the second predetermined value> the first predetermined value), a composite power supply mode,
In other cases (when the output torque of the synchronous motor is other than the above), the single power feeding mode corresponding to the small number of pole pairs among the number of pole pairs,
Select each
It is characterized by that.

A control method for a synchronous motor according to an eighteenth invention is
The power supply mode switching step includes
At each operating point of the synchronous motor represented by the rotational speed and the output torque, a power supply mode in which the input / output efficiency of the synchronous motor is higher is selected from the composite power supply mode and the single power supply mode. ,
It is characterized by that.

A control method for a synchronous motor according to a nineteenth invention is
The power supply mode switching step includes
When the operating point changes from the first operating point to the second operating point at the operating point of the synchronous motor represented by the rotational speed and the output torque, a predetermined time elapses at the second operating point. Until the power supply mode at the first operating point is maintained, and the power supply mode at the second operating point is switched after the predetermined time,
It is characterized by that.

The control method of the synchronous motor according to the twentieth invention is
The power supply mode switching step includes
When the power supply mode is switched, the distribution ratio of each of the rotating magnetic fields corresponding to the number of pole pairs required in the power supply mode before and after the switching is changed temporally so that the output torque of the synchronous motor is continuous before and after the switching. ,
It is characterized by that.

A control method for a synchronous motor according to a twenty-first aspect of the invention is
The power supply mode switching step includes
In the single power supply mode corresponding to the driving of one pole pair, the other pole is controlled so as to suppress the induced voltage generated in the winding constituting the stator due to the number of the other pole pair that is not fed (driven). Superimposing a field weakening current corresponding to the logarithm on the current in the single power supply mode,
It is characterized by that.

A control method for a synchronous motor according to a twenty-second aspect of the invention is
The rotor is
Regarding the number of pole pairs, the phase difference between the respective magnetic poles is configured with a phase difference that minimizes the peak value of the induced voltage waveform generated in the windings constituting the stator.
It is characterized by that.
A control method for a synchronous motor according to a twenty-third invention is
The number of pole pairs is two pole pairs of P1 and P2 (where P1 <P2);
The phase difference between these magnetic poles is:
Phase difference [mechanical angle (degree)] = 90 × (1 / P1-1 / P2)
Satisfy,
It is characterized by that.
A control method for a synchronous motor according to a twenty-fourth invention is
The deviation angle from the angle given by the phase difference formula is within −20% to + 20%.
It is characterized by that.

According to the first aspect of the present invention, a single rotor comprising a plurality of rotors each having a different number of pole pairs and the rotors being coaxially connected so as not to rotate relative to each other, or the number of pole pairs One rotor having a spatial magnetic flux in which different magnetic fluxes are superimposed is used as a rotor, and a stator capable of generating a plurality of rotating magnetic fields corresponding to the number of pole pairs. The configured synchronous motor has a composite power supply mode that generates a rotating magnetic field corresponding to a plurality of pole pairs and a single power supply mode that generates a rotating magnetic field corresponding to one pole pair, and the rotation speed and output of the motor is compared with a predetermined value at least one of torque, so switch the power supply mode according to a result of comparison, it is possible to minimize the losses, in the entire region of the operating point of the motor It is possible to provide an efficient electric motor.

  Further, according to the second invention, since the composite power supply mode is set when the output torque of the motor is larger than a predetermined value, the output torque of the motor used in the present invention can be fully exhibited. In addition, since the single feeding mode corresponding to the small number of pole pairs among the number of pole pairs when the rotational speed of the synchronous motor is larger than a predetermined value, the current magnetic flux frequency at this time is low, and iron loss is suppressed. The efficiency of the motor improves in the area. Further, when the output torque and the rotational speed of the synchronous motor are other than the above, that is, when the output torque is smaller than a predetermined value and the rotational speed is smaller than a predetermined value, the single power supply mode corresponding to the large number of pole pairs among the number of pole pairs is set. Therefore, low torque and large torque characteristics due to the large number of pole pairs can be obtained, and iron loss due to the current magnetic flux corresponding to the small number of pole pairs does not occur, so that the efficiency of the motor is improved in this region. The predetermined value for the output torque and the predetermined value for the rotational speed may be a variable value for the rotational speed and a variable value for the output torque, respectively. In this case, since the region is specified more strictly, the efficiency of the electric motor can be further improved.

  Further, according to the third invention, the rotational speed has at least two predetermined values, ie, a first predetermined value and a second predetermined value larger than the first predetermined value, and the rotational speed of the electric motor is the first value. A single power supply mode corresponding to a large number of pole pairs among the number of pole pairs when larger than a predetermined value, a single power supply mode corresponding to a small number of pole pairs among the number of pole pairs when the rotational speed of the synchronous motor is larger than a second predetermined value, Since the combined power supply mode is set when the rotational speed of the synchronous motor is other than the above, that is, smaller than the first predetermined value, in addition to the effect of the second invention, the power supply mode can be switched only by a rotational speed that can be easily detected. It becomes possible. In addition, since the power supply mode is not switched with respect to the load torque fluctuation of the motor, the present invention is used for such an application with a large load torque fluctuation or an application with a large output torque change demand. It is possible to provide an electric motor with little torque fluctuation and less change in operating noise.

  Further, according to the fourth invention, when the rotational speed of the motor is larger than a predetermined value, the single power supply mode corresponding to the small number of pole pairs among the number of pole pairs, the rotational speed of the synchronous motor is other than the above, that is, the rotational speed is Since the composite power supply mode is set when the value is smaller than the predetermined value, the program for determining the switching area can be further simplified in addition to the effect of the third invention.

  According to the fifth invention, the output torque has at least two predetermined values, that is, a first predetermined value and a second predetermined value larger than the first predetermined value, and the output torque of the electric motor is the first value. A single power supply mode corresponding to a large number of pole pairs among the number of pole pairs when greater than a predetermined value, a composite power supply mode when the output torque of the synchronous motor is greater than a second predetermined value, and an output torque of the synchronous motor other than the above, that is, In addition to the effect of the second aspect of the invention, in addition to the effect of the second aspect of the invention, or a change in the rotation speed when the number of pole pairs is smaller than the first predetermined value. By using the present invention for a demanding application, it is possible to provide an electric motor with little change in torque or change in operating noise that occurs at the time of switching.

  According to the sixth invention, at each operating point of the electric motor represented by the rotation speed and the output torque, either the combined power supply mode or the single power supply mode, a mode in which the input / output efficiency of the motor is high is set. Since it is selected and driven, the loss of this electric motor can be suppressed to the maximum, and the most efficient characteristic can be obtained.

  According to the seventh invention, when the operating point changes from the first operating point to the second operating point at the operating point of the electric motor represented by the rotational speed and the output torque, The power supply mode at the first operating point is maintained until a predetermined time has elapsed at the operating point, and the power supply mode at the second operating point is switched to drive after the predetermined time, so that the operating point frequently changes. By using the present invention for the purpose of the application, it is possible to prevent the slight torque fluctuation and the change of the operation sound caused by the power supply mode switching during the transition.

  According to the eighth aspect of the invention, at the time of switching the power feeding mode, each of the rotating magnetic fields corresponding to the number of pole pairs required for the power feeding mode before and after the switching is temporally changed in distribution ratio and output. Since the drive is performed so that the torque is continuous, it is possible to suppress a slight torque fluctuation and a change in operation sound caused by the power supply mode switching.

  Further, according to the ninth invention, in the single power supply mode corresponding to the driving of one pole pair, the induced voltage generated in the stator winding due to the number of the other pole pairs not driven is suppressed. Since the field weakening current corresponding to the number of pole pairs is superimposed, it is possible to ensure a voltage margin for the inverter element withstand voltage or the power supply voltage.

  Further, according to the tenth invention, with respect to the plurality of pole pairs, the phase difference between the magnetic poles is determined to be the phase difference that minimizes the peak value of the induced voltage waveform generated in the stator winding. The voltage margin for the element breakdown voltage or the power supply voltage can be maximized.

を満足するようにすると、固定子巻線に生じる誘起電圧波形のピークを最小にすることが可能であり、第１０の発明の効果を最大化できる。 According to the eleventh aspect, the number of pole pairs is two pole pairs of P1 and P2 (P1 <P2), and the phase difference between these magnetic poles is expressed by the following equation:

If the condition is satisfied, the peak of the induced voltage waveform generated in the stator winding can be minimized, and the effect of the tenth invention can be maximized.

  According to the twelfth aspect, the rate of deterioration of the peak of the induced voltage waveform generated in the stator winding is set by setting the deviation angle from the angle given by the phase difference formula to be within -20% to + 20%. Can be suppressed to about 5% of the minimum.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First Embodiment FIG. 1 is a diagram showing an example of a synchronous motor and its control device applied to the present invention. First, the configuration will be described. The electric motor is composed of one rotor 14 and a stator 11 composed of 18 divided cores 12. The windings 13 concentrated around each core are arranged in sets of 6 every 6 pieces (total 6 sets), connected in series or in parallel, and one of them is a neutral point. One of the other phases is connected, and the other is connected to the P side and N side of the power supply line via a switching element inside an inverter (not shown). This inverter is configured to control six phases. In this embodiment, the rotor has two types of pole pairs, ie, a 3-pole pair and a 6-pole pair.

  Next, the operation of this electric motor will be described. As described above, a six-phase inverter is connected to the stator, and a current may be applied so as to generate a composite sinusoidal magnetic flux corresponding to the rotor magnetic field of three and six pole pairs. The current command is rotated according to the position of the rotor in the same way as in a normal motor. However, in this motor, a composite magnetic flux corresponding to both pole pairs is generated. Since a sine wave is generated, the inverter is considered to have six phases, and the current value at each position obtained by dividing one cycle of the sine wave into six is calculated as a command value for each phase. On the other hand, since a sine wave of 6 cycles is generated for a 6 pole pair, the current command value is obtained at a position obtained by dividing one cycle of the sine wave into 3 parts. The command values for the fifth phase, the third phase, and the sixth phase are used. Thereafter, the command values of the 3 pole pair and 6 pole pair are added together, and current control is performed as the command value of the 6-phase inverter. This causes the rotor to generate torque and rotate. The driving method of the present invention can also be applied to a mechanically connected two rotors described in Japanese Patent No. 3480301. Further, although this stator is described with a divided core, the same operation can be performed with a non-divided core, or the present invention can be applied to a slotless motor. Further, the winding is not limited to concentrated winding, and can be applied to distributed winding.

  Reference numeral 14 denotes a rotor. In this embodiment, the rotor 14 includes three N-pole magnets N1 to N3 and six S-pole magnets S1 to S6. These magnets include three-pole pairs and six-pole pairs. It functions as two sets of magnets having two types of pole pairs. The two sets of magnets in this case are conceptual, and the members are not clearly separated. For one current constituting a composite current supplied to the stator winding, 3 magnets are used. Means that there is one set of magnets that behave as a set of pole pairs, and that there is one set of magnets that behaves as a set of 6 pole pairs for the other current that makes up the composite current The magnets S1 to S6 and N1 to N3 simultaneously function as both sets of magnets. This will be described in detail with reference to FIG. Hereinafter, for convenience of drawing and explanation, the rotor magnets are illustrated and described as N poles and S poles, but the operation and effect of the invention are the same even if the configuration and arrangement of the NS poles are reversed. Please keep in mind. Further, the N-pole and S-pole magnets are magnets in which the magnetization direction is in the radial direction (in the opposite direction) so that the direction of the magnetic field lines is in the radial direction, and the N pole is on the outer side (stator side). The poles are arranged on the outside (stator side). In this embodiment, a magnet is used in which the magnetizing direction is arranged in the radial direction. However, the present invention is not limited to this arrangement, and there is no problem as long as the magnetic lines of force are directed substantially in the radial direction. It may be.

  As shown in FIG. 1, the control device 20 that controls the electric motor includes power supply mode switching means 22. Based on a predetermined value (threshold value) which will be described later, the power feeding mode switching means 22 switches to the optimum one from the three power feeding modes of the composite power feeding mode, the single power feeding mode (high order), and the single power feeding mode (low order). Actually, for example, the power supply mode switching means 22 performs mode switching by giving a power supply mode switching signal to an inverter (or an upper circuit such as an inverter control device) not shown. The motor control device includes a number of circuits / functions other than the power supply mode switching means, but portions not related to the present invention are not shown.

  FIG. 2 is an explanatory diagram of rotor generation according to the first embodiment. FIG. 2A is a rotor of a motor having a two-rotor structure, in which an inner rotor is a three-pole pair and an outer rotor is a rotor. 6 magnet pairs are provided. FIG. 2B shows the magnets arranged in two layers on the surface layer of the inner rotor. Although slight phase adjustment is performed at the time of arrangement, details thereof will be described later. Referring to FIG. 2B, the rotor 14A has two types of magnets (N pole and S pole) having different magnetization directions in contact with each other at several positions. As is well known, when magnets having different magnetization directions are bonded together, the magnets are equivalent to those without magnets if the magnetic forces of the magnets are the same.

  Therefore, FIG. 2 (C) shows that the magnets are excluded from the part where the magnets of different magnetization as viewed in the radial direction are bonded together, and this rotor 14 has N pole magnets N1 to N3 and S pole magnets. S1 to S6 are included. As a result, the rotor 14 that generates the composite magnetic flux CF of the three-pole pair and the six-pole pair as shown by a curved line is completed. Note that the rotor used in the present invention has a configuration in which an inner rotor and an outer rotor are integrated without removing a portion of a magnet in contact with a magnet having a different polarity, as shown in FIG. It should be noted that the configuration is sufficient, and the effect of miniaturization and current reduction can be obtained, and the same composite magnetic flux CF (not shown in FIG. 2B) is generated as in FIG. . That is, the rotor 14A is a rotor having a configuration in which the first rotor of the inner rotor and the second rotor of the outer rotor are integrated. Of course, the configuration of FIG. 2C from which unnecessary magnets are removed is more effective in improving torque by reducing the inertia of the deleted magnet, reducing the weight of the motor, and reducing the cost of the deleted magnet. .

  In FIG. 2C, the area from which unnecessary magnets are removed is a space, and air occupies the area, but the area occupied by the air functions to prevent magnetic flux from passing therethrough. That is, it is necessary to place a member other than a material that easily allows magnetic flux, such as iron, in this region from which the magnet has been removed, but space (air) is usually sufficient. Of course, a member that is difficult to pass magnetic flux other than air may be provided in the region.

  Next, the driving method of this embodiment will be described. FIG. 3 is a power supply mode map applied in this embodiment. As a threshold for dividing each power supply mode region, the power supply mode switching means 22 of the motor control device 20 shown in FIG. 1 includes a predetermined torque value and a predetermined rotational speed value. The switching means 22 performs region determination by comparing the threshold value with the current operating point of the motor, and drives the motor in a power supply mode corresponding to each region. When the output torque of the electric motor is larger than a predetermined torque value, the motor is driven in the composite power supply mode. As described above, this is current control corresponding to both the three-pole pair and the six-pole pair, and a single motor physique can generate a torque twice that of a normal electric motor. Further, when the rotation speed of the electric motor is greater than a predetermined value, the motor is driven in the low-order single power supply mode. This is a low-order, that is, current control corresponding to the three-pole pair. As a result, the current corresponding to the six-pole pair that has been energized in the composite power supply mode is removed. By removing the magnetic flux, the electric motor can be driven with high efficiency.

  Furthermore, when the output torque of the electric motor is smaller than the torque predetermined value and the rotation speed is smaller than the rotation speed predetermined value, the motor is driven in a high-order single power supply mode. This is high-order, that is, current control corresponding to six-pole pairs, and this region is covered with the number of high-order pole pairs that can take a large output torque at a low speed without generating excessive current magnetic flux. Iron loss is reduced and the motor can be driven with high efficiency.

  In the present embodiment, the predetermined torque value and the predetermined rotational speed value are constant values, but may be variable values for the rotational speed and variable values for the output torque, respectively. In this case, the determination program in the controller becomes complicated, but the efficiency of the electric motor can be further improved because the region is specified more strictly. Further, the current output torque of the electric motor may use a detection signal of the torque detector, may be estimated from the rotation speed and the energization current, or may be substituted with a torque command value to the controller. The current rotation speed of the electric motor may be a detection signal of a rotation angle detector provided in the electric motor, or may be a detection signal if a rotation speed detector is provided on the load side.

The driving method of the second embodiment will be described. FIG. 4 is a power supply mode map applied in this embodiment. As threshold values that delimit the regions of the respective power supply modes, a motor controller (not shown) has two threshold values of a predetermined rotational speed value 1 and a predetermined rotational speed value 2. When the rotation speed of the electric motor is smaller than the rotation speed predetermined value 1, the motor is driven in the composite power supply mode. Further, when the rotation speed of the electric motor is equal to or higher than the rotation speed predetermined value 1 and smaller than the rotation speed predetermined value 2, the motor is driven in a high-order single power supply mode. Further, when the rotation speed of the electric motor is equal to or higher than the rotation speed predetermined value 2, the motor is driven in the low-order single power supply mode. The operation in each region is the same as in the first embodiment. Further, the effect of the third invention can be obtained.

Third Embodiment A driving method of this embodiment will be described. FIG. 5 is a power supply mode map applied in this embodiment. A motor controller (not shown) is provided with a threshold value for a predetermined rotational speed as a threshold value for dividing each power supply mode region. When the rotation speed of the electric motor is smaller than a predetermined value, the motor is driven in the composite power supply mode. Further, when the rotation speed of the electric motor is equal to or higher than the rotation speed predetermined value, the motor is driven in a low-order single power supply mode. The operation in each region is the same as in the first embodiment. The effect of the fourth invention will be obtained.

Fourth Embodiment A driving method of this embodiment will be described. FIG. 6 is a power supply mode map applied in this embodiment. As threshold values that delimit the regions of the respective power supply modes, a motor controller (not shown) has two threshold values, torque predetermined value 1 and torque predetermined value 2. When the output torque of the motor is smaller than the torque predetermined value 1, the motor is driven in the low-order single power supply mode. When the output torque of the electric motor is equal to or greater than the torque predetermined value 1 and smaller than the torque predetermined value 2, the motor is driven in a high-order single power supply mode. Further, when the output torque of the electric motor is equal to or greater than the torque predetermined value 2, it is driven in the composite power supply mode. The operation in each region is the same as in the first embodiment. The effect of the fifth invention will be obtained.

Fifth Embodiment A driving method of this embodiment will be described. In this embodiment, at each operating point of the electric motor represented by the rotation speed and the output torque, either the composite power supply mode or the single power supply mode is selected and driven with a mode having high input / output efficiency of the motor. This is because the motor efficiency at each operating point in the combined power supply mode and each single power supply mode is obtained by analysis or experiment in advance, and the power supply mode with the highest motor efficiency at each operating point is extracted and mapped to the power supply mode map. deep. The motor controller is provided with this power supply mode map, and the power supply mode is selected in comparison with the current operating point of the motor. Therefore, according to the present embodiment, the loss of the electric motor can be suppressed to the maximum, and the most efficient characteristic can be obtained.

Sixth Embodiment In this embodiment, when the operating point changes from the first operating point to the second operating point at the operating point of the motor represented by the rotational speed and the output torque, The power supply mode at the first operating point is maintained until a predetermined time elapses at the operating point, and the power supply mode at the second operating point is switched after the predetermined time. FIG. 7 is a diagram illustrating a case where the operating point changes. This power supply mode map is equivalent to that of the first embodiment. On the operating point of FIG. 7, the operating point A is driven in the single power supply mode corresponding to the 6-pole pair (higher order side), and then crosses the rotational speed predetermined value during the transition to the operating point B. At this time, the mode is not switched to the single power supply mode corresponding to the three-pole pair (low order). After that, the operating point B is reached, and it is detected that no transition of the operating point occurs for a predetermined time (for example, 1 second), and then the mode is switched to the single power supply mode corresponding to the three-pole pair which is the power supply mode in this region. In this way, although the motor efficiency during the operating point transition is lower than the effect of the first embodiment, a slight torque fluctuation or a change in the operating noise due to the power feeding mode switching during the transition occurs. It can be lost.

FIG. 8 illustrates an example in which the present embodiment is applied in the power supply mode map of the fourth embodiment. Both the operating point A and the operating point B are single power supply modes corresponding to three pole pairs (low order), but during the transition, the single power supply mode corresponding to six pole pairs (high order) is passed. In this case as well, the power feeding mode is not switched during the transition as described above. As described above, this embodiment detects that a predetermined time has passed at an arbitrary operating point, and then switches to the power supply mode for that region. As a means for detecting that a predetermined time has passed at an arbitrary operating point, a time change rate between the output torque detector and the rotational speed detector is calculated as needed, and the time during which these values are less than a predetermined value close to zero It can be realized by counting. In the case of a region that can be realized only in the original power supply mode, such as when passing through a high-speed large torque region during mode transition, the driving is performed in the original power supply mode, not limited to the above.

In the seventh embodiment, when the power feeding mode is switched, the output torque is made continuous by changing the distribution ratio of each of the rotating magnetic fields corresponding to the number of pole pairs required in the power feeding mode before and after the switching. To drive. For example, when switching from the six-pole pair single-feed mode to the three-pole pair single-feed mode, the current corresponding to the six-pole pair is gradually reduced and overlapped with this to increase the current corresponding to the three-pole pair. At this time, each current is distributed so that the torque generated by the addition of both currents matches the torque at the operating point at that time. In this embodiment, the effect of the eighth invention can be obtained.

Eighth Embodiment In a single power supply mode corresponding to driving of one pole pair, a field weakening current corresponding to the number of other pole pairs not driven is superimposed on the control current. In the above-described embodiment, as an example, this corresponds to adding the field-weakening current corresponding to the 6-pole pair when the single power supply mode corresponding to the 3-pole pair is driven. In this embodiment, the effect of the ninth invention can be obtained.

を満足するようにすると、固定子巻線に生じる誘起電圧波形のピークを最小にすることが可能であり。ここでは、第１０、第１１の発明の効果が得られることとなる。 Ninth Embodiment FIG. 9 is a diagram for explaining the phase relationship between two pole pairs generated in a rotor. 9C shows a rotor that generates a composite magnetic flux of two-pole pairs and four-pole pairs. When the phase difference of the magnetic flux corresponding to the number of pole pairs is defined as shown in (c), the magnetomotive force distribution of the rotor is (a). Further, the induced voltage waveform generated in the stator winding by the rotation of the rotor is (b). Here, when the above-mentioned phase difference is changed and the peak value of the induced voltage waveform is examined, (d) is obtained. In the above embodiments, the control current corresponding to the number of pole pairs may not be supplied. At this time, it is desirable that the induced voltage corresponding to the number of pole pairs is small. Therefore, as can be seen from (d), it can be minimized by setting the phase difference between the two pole pairs to 22.5 degrees (mechanical angle). It was found that the peak value of the induced voltage waveform can be minimized if the following formula is satisfied as a general formula. That is, the number of pole pairs is P1 and P2 (P1 <P2), and the phase difference between these magnetic poles is

If it is made to satisfy, it is possible to minimize the peak of the induced voltage waveform generated in the stator winding. Here, the effects of the tenth and eleventh inventions are obtained.

  FIG. 10 shows the result of examining the phase shift rate with respect to the value obtained from the above equation on the horizontal axis, and the deterioration rate from the value at which the peak value of the induced voltage is minimized on the vertical axis. As shown in the graph for explaining the relationship between the phase shift rate and the deterioration rate, if the phase shift angle from the angle given by the phase difference formula is set within -20% to + 20%, it occurs in the stator winding. The deterioration rate of the peak of the induced voltage waveform can be suppressed to about 5% at the minimum.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each member, each means, each step, etc. can be rearranged so that there is no logical contradiction, and a plurality of members, means, steps, etc. can be combined or divided into one. Is possible. In the embodiment, the description has been given by taking the rotor having two sets of pole pairs as an example, but the present invention is also applicable to a rotor having three or more pairs of pole pairs. In this case, the number of pole pairs having the smallest number of pole pairs is set as the number of pole pairs having the smallest number of pole pairs, and the number having the largest number of pole pairs is designated as the number of pole pairs having the largest number of pole pairs.

It is a figure which shows one example of the synchronous motor of 1st Example, and its control apparatus. It is a rotor production | generation explanatory drawing of a 1st Example. It is the electric power feeding mode map explaining a 1st Example. It is an electric power feeding mode map explaining a 2nd Example. It is an electric power feeding mode map explaining a 3rd Example. It is the electric power feeding mode map explaining a 4th Example. It is a figure which shows the electric power feeding mode map and operating point transition explaining a 6th Example. It is a figure which shows the electric power feeding mode map and operating point transition explaining a 6th Example. It is a figure explaining the 9th Example. It is a figure explaining the 9th Example (relationship between a phase shift rate and a deterioration rate).

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Stator 12 Core 13 Winding 14 Rotor 14A Rotor 20 Controller 22 Feeding mode switching means A, B Operating point CF Composite magnetic flux N1-N3 N pole magnet S1-S6 S pole magnet

Claims (13)

One rotor having a plurality of rotors each having a different number of pole pairs and coaxially connecting the rotors, or one having a spatial magnetic flux in which a plurality of magnetic fluxes having different numbers of pole pairs are superimposed. A control device for a synchronous motor, comprising: one of the rotors; and a stator capable of generating a plurality of rotating magnetic fields corresponding to the number of pole pairs.
Comparing at least one of the rotational speed and output torque of the synchronous motor with a predetermined value, and corresponding to the result of the comparison , corresponding to the combined power supply mode for generating a rotating magnetic field corresponding to the number of pole pairs and the number of pole pairs Power supply mode switching means for switching between a single power supply mode for generating a rotating magnetic field,
A control device for a synchronous motor including: In the synchronous motor control device according to claim 1,
The power supply mode switching means is
When the output torque of the synchronous motor is greater than a predetermined value, the combined power supply mode,
When the rotational speed of the synchronous motor is larger than a predetermined value, a single power supply mode corresponding to the number of pole pairs smaller than the number of pole pairs,
In other cases, the single power supply mode corresponding to a large number of pole pairs among the plurality of pole pairs,
Select each
The control apparatus of the synchronous motor characterized by the above-mentioned. In the synchronous motor control device according to claim 1,
The power supply mode switching means is
When the rotational speed of the synchronous motor is greater than a first predetermined value, the single power supply mode corresponding to a large number of pole pairs among the number of pole pairs,
When the rotational speed of the synchronous motor is greater than a second predetermined value (where the second predetermined value> the first predetermined value), the single power supply mode corresponding to the smaller number of pole pairs out of the number of pole pairs;
In other cases, the combined power supply mode,
Select each
The control apparatus of the synchronous motor characterized by the above-mentioned. In the synchronous motor control device according to claim 1,
The power supply mode switching means is
When the rotational speed of the synchronous motor is greater than a predetermined value, the single power supply mode corresponding to the small number of pole pairs among the number of pole pairs,
Otherwise, the combined power supply mode,
Select each
The control apparatus of the synchronous motor characterized by the above-mentioned. In the synchronous motor control device according to claim 1,
The power supply mode switching means is
When the output torque of the synchronous motor is greater than a first predetermined value, the single power supply mode corresponding to the number of pole pairs that is large among the number of pole pairs,
When the output torque of the synchronous motor is larger than a second predetermined value (where the second predetermined value> the first predetermined value), a composite power supply mode,
In other cases, the single power supply mode corresponding to the small number of pole pairs among the number of pole pairs,
Select each
The control apparatus of the synchronous motor characterized by the above-mentioned. In the synchronous motor control device according to claim 1,
The power supply mode switching means is
At each operating point of the synchronous motor represented by the rotational speed and the output torque, a power supply mode in which the input / output efficiency of the synchronous motor is higher is selected from the composite power supply mode and the single power supply mode. ,
The control apparatus of the synchronous motor characterized by the above-mentioned. In the control apparatus of the synchronous motor of any one of Claims 1-6,
The power supply mode switching means is
When the operating point changes from the first operating point to the second operating point at the operating point of the synchronous motor represented by the rotational speed and the output torque, a predetermined time elapses at the second operating point. Until the power supply mode at the first operating point is maintained, and the power supply mode at the second operating point is switched after the predetermined time,
The control apparatus of the synchronous motor characterized by the above-mentioned. In the control apparatus of the synchronous motor of any one of Claims 1-7,
The power supply mode switching means is
When the power supply mode is switched, the distribution ratio of each of the rotating magnetic fields corresponding to the number of pole pairs required in the power supply mode before and after the switching is changed temporally so that the output torque of the synchronous motor is continuous before and after the switching. ,
The control apparatus of the synchronous motor characterized by the above-mentioned. In the synchronous motor control device according to any one of claims 1 to 8,
The power supply mode switching means is
In the single power supply mode corresponding to the driving of one pole pair, the other pole is controlled so as to suppress the induced voltage generated in the winding constituting the stator due to the number of the other pole pair that is not fed (driven). Superimposing a field weakening current corresponding to the logarithm on the current in the single power supply mode,
The control apparatus of the synchronous motor characterized by the above-mentioned. In the control apparatus of the synchronous motor of any one of Claims 1-9,
The rotor is
Regarding the number of pole pairs, the phase difference between the respective magnetic poles is configured with a phase difference that minimizes the peak value of the induced voltage waveform generated in the windings constituting the stator.
The control apparatus of the synchronous motor characterized by the above-mentioned. In the control apparatus of the synchronous motor of any one of Claims 1-10,
The number of pole pairs is two pole pairs of P1 and P2 (where P1 <P2),
The phase difference between these magnetic poles is:
Phase difference [mechanical angle (degree)] = 90 × (1 / P1-1 / P2)
Satisfy,
The control apparatus of the synchronous motor characterized by the above-mentioned. In the synchronous motor control device according to claim 11,
The deviation angle from the angle given by the phase difference formula is within −20% to + 20%.
The control apparatus of the synchronous motor characterized by the above-mentioned. One rotor having a plurality of rotors each having a different number of pole pairs and coaxially connecting the rotors, or one having a spatial magnetic flux in which a plurality of magnetic fluxes having different numbers of pole pairs are superimposed. A method of controlling a synchronous motor including any one of the rotors, and a stator capable of generating a plurality of rotating magnetic fields corresponding to the number of pole pairs,
In accordance with the rotational speed and output torque of the synchronous motor, a composite power supply mode that generates a rotating magnetic field corresponding to the number of pole pairs, and a single power supply mode that generates a rotating magnetic field corresponding to the number of pole pairs. Power supply mode switching step for switching,
Control method of synchronous motor including

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